*{
    margin: 0px;
    padding: 0px;
    font-family: "微软雅黑";
}
#head,
#foot,
#main
{
    height: 100px;
    width: 1200px;
    /*width: 85%;*/
    background-color: goldenrod;
    text-align: center;
    font-size: 48px;
    line-height: 100px;
    margin: 0 auto;
}
#head div{
    display: none;
    font-size: 20px;
    height: 30px;
    width: 100px;
    background-color: green;
    float: right;
    line-height: 30px;
    margin-top: 35px;
}
#head ul{
    width: 80%;
}
#head ul li{
    width: 20%;
    float: left;
    text-align: center;
    list-style: none;font-size: 20px;
}
#main{
    height: auto;
    margin: 10px auto;
    overflow: hidden;
}
.left,
.center,
.right{
    height: 600px;
    line-height: 600px;
    float: left;
    width: 20%;
    background-color: red
}
.center{
    width: 60%;
    border-left: 10px solid #FFF;
    border-right: 10px solid #FFF;
    box-sizing: border-box;
}
@media only screen and (max-width: 1200px) {
    #head,
    #foot,
    #main{
    width: 100%;
    }
}
@media only screen and (max-width: 980px) {
    .right{
        display: none;
    }
    .left{
        width: 30%;
    }
    .center{
        width: 70%;
        border-right: hidden;
    }
}
@media only screen and (max-width: 640px) {
    .left,
    .center,
    .right{
        width: 100%;
        display: block;
        height: 200px;
        line-height: 200px;
    }
    .center{
        border: hidden;
        border-top: 10px  solid #FFFFFF;
        border-bottom: 10px solid #FFFFFF;
        height: 600px;
        line-height: 600px;
    }
    #head ul{
        display: none;
    }
    #head div{
        display: block;
    }
}